Well, I am not a SQL Server guy but this is - again - an important release. Besides all the real great technical enhancements SP2 is quite remarkable from a Virtualization perspective. From the first paragraph of the announcement: "In addition, Microsoft announced that it is expanding virtualization use rights to allow unlimited virtual instances on servers that are fully licensed for SQL Server 2005 Enterprise Edition."

You can find more about licensing options for SQL Server on the "How to buy Microsoft SQL Server" website.